Sorry for taking so long to reply. I can only find a '94 truck service manual, but I think the circuitry is the same.
There are two different circuits feeding the dimmer switch. Pop the trim cover off the multifunction switch, then use a test light or digital voltmeter to measure the voltages on the wires. There will be 12 volts on the light green / white wire. That's the one that feeds the "flash-to-pass" high beams. The light green wire should have 12 volts when the headlight switch is turned on. If it's there, replace the multifunction switch or look for an overheated connector terminal. If the voltage is not there, replace the head light switch or look for an overheated terminal there.
The switches should all be plugged in when making voltage measurements because when they're unplugged, even a severely overheated terminal will pass enough current for the voltmeter to pick up the voltage. That will result in a false reading. Think of a severe kink in a garden hose. As long as it's not 100 percent blocked, you will still have full pressure at the end of the hose, as long as the nozzle is turned off. That pressure is what you're reading when a switch is disconnected. Open the hose nozzle and no water can flow past the kink. Connect the switch and no current can flow past the overheated terminal. In both cases there will be no pressure, (voltage) at the end where you are measuring. That's the accurate measurement.
If you find a discolored, overheated terminal, it can be cut out of the plastic connector body and be replaced with a generic crimp-on terminal, but solder it too for a better connection. If the wire was also overheated, it will be hardened and difficult to solder to. Cut off about 4 inches of it and splice in a new piece the same diameter.
Friday, February 4th, 2011 AT 10:09 PM